For some time, electronic percussion instruments that mimic an acoustic hi-hat cymbal have been produced where the hi-hat timbre is controlled by the amount that the foot pedal is depressed (from being stepped on by a performer). In other words, the hi-hat timbre is controlled in conformance with the amount of change in the position of the upper cymbal based on the amount to which the foot pedal is depressed from being stepped on. In Japanese Unexamined Patent Application (Kokai) Publication Number 2005-195981, an electronic hi-hat cymbal is disclosed in which the upper cymbal moves up and down in conformance with the amount that the foot pedal is depressed to simulate a performance feeling of an acoustic hi-hat cymbal.
FIGS. 6(a) and 6(b) show an electronic hi-hat 80 similar to that disclosed in Japanese Unexamined Patent Application (Kokai) Publication Number 2005-195981. FIG. 6(a) is a lateral cross-section drawing of the entire electronic hi-hat unit, but with a lateral view (without cross-section) of the upper cymbal 100 and the lower cymbal 200. A cross-section view of the upper cymbal 100, lower cymbal 200 and the portion between the upper and lower cymbals is shown in the drawing of FIG. 6(b).
As is shown in FIG. 6(a), the electronic hi-hat 80 is furnished with the upper cymbal 100, the lower cymbal 200, an extension rod 420 to which the upper cymbal is linked in a manner that allows vibration of the upper cymbal 100, and a hollow shaft member 410 to which the lower cymbal is linked in a manner that allows vibration of the lower cymbal 200. A spring 430 is placed in the inner lower end of the hollow shaft member 410. The electronic hi-hat 80 also includes a treading foot pedal 440, a joint 450 that links the extension rod 420 and the foot pedal 440, and a leg section 460 linked to the hollow shaft member 410, for supporting the electronic hi-hat 80 in a standing orientation.
The extension rod 420 is linked on the lower portion to the foot pedal 440 through the joint 450 in a configuration such that the extension rod 420 moves up and down in conformance with the treading operation of the foot pedal 440. The upper cymbal 100 is linked by a linking fitting to the upper portion of the extension rod 420 in a manner such that the upper cymbal is able to vibrate and move up and down together with the up and down movement of the extension rod 420, in conformance with the treading operation of the foot pedal 440.
The lower portion of the extension rod 420 passes through the upper hollow shaft 411 and the lower hollow shaft 412, and also passes through the spring 430 inside the lower hollow shaft 412. The spring 430 is held sandwiched between the bottom of a knurl section 420a on the extension rod 420 and the top of a knurl section 412a of the lower hollow shaft 412, such that the extension rod 420 is always subjected to a force biasing the rod 420 upward. As a result, when the treading operation of the foot pedal 440 is not being carried out, the upper cymbal 100 and the lower cymbal 200 are separated at a specified interval.
Next, an explanation will be given regarding the upper cymbal 100 and the lower cymbal 200 while referring to FIG. 6(b). FIG. 6(b) shows the upper cymbal 100 and the lower cymbal 200 in the open position or separated state. When the foot pedal 440 is stepped on by a sufficient amount, the upper cymbal 100 and the lower cymbal 200 will be in a closed position in which the upper cymbal 100 and the lower cymbal 200 are in a state of close contact.
The upper cymbal 100 has a striking surface 110 that is formed using rubber on the top surface. On the side of the upper cymbal 100 facing opposite to the side of the striking surface 110, a vibration sensor 70 is disposed on a vibration sensor attaching frame 120. The vibration sensor 70 is a sensor that detects the vibration level of the vibrations of the upper cymbal 100 due to the striking of the upper cymbal 100 or the contact between the upper cymbal 100 and the lower cymbal 200 and is, for example, a piezoelectric sensor. When the vibration sensor detects the vibration level, an analog electrical signal that corresponds to the vibration level is transmitted to a stereo jack 150 linked for output by a connecting cable (not shown in the drawing). The analog electrical signal is input via the plug 130, the cable 131, and the stereo jack 230, to the stereo jack 250 of the lower cymbal 200. The stereo jack 250 is linked for input from the stereo jack 150 and output from an output terminal (not shown in the drawing).
As shown in FIG. 6(b), the displacement sensor 60 is arranged between the upper cymbal 100 and the lower cymbal 200. The displacement sensor 60 is configured with a circular sensor sheet that is housed in the bottom of the inside of a hollow cylinder, the top of which is open. The displacement sensor 60 is further configured with a conical shaped coil spring that is arranged on the sensor sheet and that widens from the top downward, and a cover that is in contact with the top of the coil spring. When the foot pedal 440 is stepped on, the gap between the upper cymbal 100 and the lower cymbal 200 closes by an amount in conformance with the amount that the foot pedal has been depressed.
As the foot pedal descends by being stepped on, the cover section is pressed downward and the coil spring is pressed against the cushion sheet and is compressed and changes shape in the vertical direction due to the compression force. The sheet section is used for electrical detection of the changes in shape by the coil spring caused by the compression in the vertical direction. In that manner, the amount that the foot pedal 440 is depressed and, thus, the change in the position of the upper cymbal 100 (hereafter, referred to as the “upper cymbal position”) is detected. When the conical shaped coil spring compresses and changes shape due to the foot pedal 440 being depressed, the coil spring presses against a resistor-printed sheet material of the sensor sheet section, to press a portion of the resistor-printed sheet material against a carbon-printed circuit board. As a result, conductive ink of the resistor-printed sheet material comes into contact with an electrode pattern of the carbon-printed circuit board and the electrical resistance value of the carbon printed circuit board changes. This electrical resistance value changes in conformance with the amount of the pressure deformation of the coil spring and, thus, in conformance with the upper cymbal position due to the amount that the foot pedal 440 is depressed. The electrical resistance value is detected via an output terminal (not shown in the drawing).
In this manner, an electronic hi-hat cymbal configuration has been made such that the upper cymbal is moveable relative to the lower cymbal and the position of the upper cymbal 100 (the upper cymbal position) is detected by the displacement sensor 60. In addition, if that the upper cymbal 100 is vibrated due to the striking of the upper cymbal or due to the foot pedal being stepped on by a sufficient amount to cause the upper cymbal to come into contact with the lower cymbal 200, a musical tone is produced that conforms to the upper cymbal position that has been detected by the displacement sensor 60. At that time, the vibration sensor 70 detects the vibration level of the upper cymbal 100 and, if the vibration level exceeds a specified threshold value, a trigger signal is output to the sound source that instructs the audible generation of the musical tone.
FIG. 7 is a drawing that shows, visually, the relationship between the upper cymbal position that has been detected by the displacement sensor 60 and the timbre of the musical tone that is generated by the sound source. The horizontal axis shows the displacement sensor values and the vertical axis shows the levels of the musical tones that are generated. The displacement sensor values that are shown on the horizontal axis correspond to the relative positions of the upper cymbal 100 and the lower cymbal 200, where the left end of the horizontal axis corresponds to the cymbals being in close contact, with the values going toward the right correspond to increasing separations between the upper cymbal 100 and the lower cymbal 200. The range in which the displacement sensor values are smaller than a specified threshold value is called the closed position, while the range in which they are greater than a specified threshold value is called the open position.
There are five types of hi-hat sounds (open sound, half sound, slightly open sound, closed sound, and press sound) that are assigned correspondingly to the output ranges for the displacement sensor values. The open sound, half sound, and slightly open sound, which correspond to the open position, are classified as the musical tones of the open group. The closed sound and press sound, which correspond to the closed position, are classified as the musical tones of the closed group. The cross-fading of the each of the musical tones is done with the musical tones of the open group (the open sound, half sound, and slightly open sound) in conformance with the displacement sensor values. Similarly, cross-fading is done with the musical tones of the closed group (the closed sound and the press sound) in conformance with the displacement sensor values.
In addition, the musical tones of the open group and the musical tones of the closed group, as is the case with an acoustic hi-hat cymbal, are switched mutually exclusively at a specified threshold value of the displacement sensor values.
The sound source is controlled such that when the foot pedal is stepped on and the displacement sensor value becomes a specified threshold value or lower at the time that the upper cymbal position is at the open position and a musical tone of the open group is generated, an instruction is issued for the generation of a musical tone of the closed group and the musical tone of the open group that is currently being produced rapidly attenuates (truncates) and, together with this, a musical tone of the closed group is generated.
However, with an electronic hi-hat such as that described above, when the foot pedal has not been depressed, but the upper cymbal is struck with a stick or the like with a force strong enough to cause the upper cymbal to drop such that the position of the upper cymbal reaches the threshold value, the cymbal sound is extinguished even though this was not the intention of the performer.
FIGS. 8(a)-(c) show timing charts in which that event is represented, where the time is shown on the horizontal axis and the displacement sensor value is shown on the vertical axis. The condition of the musical tone that is generated by the sound in the case where the displacement sensor value has changed in the above-noted manner is shown in FIGS. 8(b) and (c).
FIG. 8(b) shows the time on the horizontal axis and the level of a musical tone of the open group that is generated by the sound source on the vertical axis. Similarly, FIG. 8(c) shows the time on the horizontal axis and the level of the musical tone of the closed group that is generated by the sound source on the vertical axis.
FIG. 8(a) shows the case in which, when the displacement sensor is at an open position that is in the vicinity of the threshold value (indicated by the alternating long and short dashed line), the upper cymbal 100 has been struck at time a. As shown in FIG. 8(a), the displacement sensor value starts to drop from time a, goes below the specified threshold value at time b, and becomes one of a closed position.
Since the upper cymbal 100 has been struck at time a, as is shown in FIG. 8(b), the generation of a musical tone of the open group begins. Next, since at time b, the upper cymbal 100 changes from the open position to the closed position, the musical tone of the open group that is being generated rapidly attenuates. At the same time, as is shown in FIG. 8(c), a waveform of the closed group is generated. After that, at time c, the musical tone of the open group is again generated with the return of the displacement sensor value to the original value and the musical tone of the closed group attenuates. Accordingly, in the interval from time b to c, a rapid attenuation is carried out of the musical tone of the open group and the generation of a musical tone of closed group occurs that was not intended by the performer.
However, such unintended effects can be avoided with embodiments of the present invention in which an electronic percussion instrument may be controlled to provide a musical tone that is intended by the performer.